Zone isolation control system for transport refrigeration units

Abstract

Multi-zone transport refrigeration units (TRUs). A combination of temperature controlled flow of cold air and time controlled refrigerant distribution is used to improve cooling performance and reduce power consumption. This dual-control zone isolation system makes it possible to use solar panels to power the TRU.

What is claimed is: 
     
         1 . A high efficiency battery powered transport refrigeration unit with zone isolation comprising:
 A. a refrigeration system wherein timer controls are used to limit refrigerant flow from a freezer zone to remote evaporators, said remote evaporators being located in refrigeration zones;   B. a refrigeration air handling system wherein air is extracted directly from a post evaporator cold-air chamber of said host freezer zone, said extracted air being distributed to each said refrigeration zone to control a single zone temperature, or multiple temperatures in multiple zones, by airflow control using a combination of fans, ducts, gates and air temperature controllers.   
     
     
         2 . The high efficiency battery powered TRU with zone isolation as claimed in  claim 1  wherein, in addition, there is a battery that powers said TRU refrigeration system that consumes less than 18 Kwh of electrical energy. 
     
     
         3 . A high efficiency battery powered TRU as claimed in  claim 2  wherein, in addition, said zone isolation consists of a knock sensor detector (not in the drawings, or numbered) for liquid refrigerant returning to a compressor that:
 i. switches on a return line heater keeping the returning refrigerant in gas phase, and 
 ii. alternatively shuts off said refrigeration system. 
 
     
     
         4 . A high efficiency battery powered TRU as claimed in  claim 2  that, in addition, includes a sensor (not in drawings) that detects a refrigerator door open condition (not in the drawings) and sends a signal to said zone isolation controller (not in the drawings) to completely shut down said refrigerator or reduce its cooling duty cycle. 
     
     
         5 . A high efficiency battery powered TRU as claimed in  claim 2  wherein, in addition, there is a compressor driven by a motor selected from the group consisting of:
 i. a direct current brushed motor; 
 ii. direct current brushless motor, 
 iii. an induction alternative current motor with a direct current to alternate current converter. 
 
     
     
         6 . A high efficiency battery powered TRU as claimed in  claim 5  wherein the motor is a separate component from the compressor or integral with the compressor. 
     
     
         7 . A high efficiency battery powered TRU as claimed in  claim 1  wherein, in addition, wherein said refrigeration air handling system is conducted wherein return air is directed through one side of said evaporator and then its direction is reversed to make said air pass through an opposite side of said evaporator. 
     
     
         8 . A high efficiency battery powered TRU as claimed in  claim 1  wherein there is, in addition, a thermoelectric device used as a sub-cooler to add capacity to a condenser and separately used to provide cooling for said temperature sensors. 
     
     
         9 . A high efficiency battery powered TRU as claimed in  claim 2  wherein a solar panel is used to charge said battery and run said TRU refrigeration system. 
     
     
         10 . A high efficiency battery powered TRU as claimed in  claim 1  wherein said solar panel is the only power generation source and said power generated is sufficient to supply all the power necessary to run said refrigeration unit. 
     
     
         11 . A high efficiency battery powered TRU as claimed in  claim 1  wherein there is, in addition, a backup wheel generator system that only makes power during deceleration. 
     
     
         12 . A high efficiency battery powered TRU as claimed in  claim 11  wherein said high efficiency battery powered TRU is programed to continuously produce power during emergency low-battery voltage situations. 
     
     
         13 . An electric power generation plant comprising a fleet of high efficiency battery powered TRUs as claimed in  claim 1  that are equipped with solar panels, ganged together in a charging network. 
     
     
         14 . A high efficiency battery powered TRU as claimed in  claim 1  wherein airflow ducts are recessed into the ceiling of said refrigeration chamber. 
     
     
         15 . A high efficiency battery powered TRU as claimed in  claim 1  wherein cold plates composed of eutectic solutions or phase change materials are used to cool refrigeration chambers and battery assemblies. 
     
     
         16 . A high efficiency battery powered TRU as claimed in  claim 1  wherein a box containing a battery assembly is filled with expanded glass beads. 
     
     
         17 . A high efficiency battery powered TRU as claimed in  claim 1  wherein a box containing a battery assembly is manufactured from expanded glass aggregate panels.